CONGER EEL. 197 



est, in one or even two seasons; but this, 

 as well as many other particulars, can 

 only be ascertained by new observations 

 and experiments. Block states, that they 

 grow slowly, and mentions that some had 

 been kept in the same pond for fifteen 

 years. As very large eels, after having 

 migrated, never return to the river again, 

 they must (for it cannot be supposed that 

 they all die immediately in the sea) remain 

 in salt water; and there is great probability 

 that they are then confounded with the 

 conger, which is found of different colours 

 and sizes from the smallest to the largest 

 from a few ounces to one hundred pounds 

 in weight. The colour of the conger is 

 generally paler than that of the eel; but, 

 in the Atlantic, it is said that pale congers 

 are found on one side of the Wolf Rock, 

 and dark ones on the other. The conger 

 has breathing tubes, which are said not to 

 be found in the other eel; but to determine 

 this would require a more minute examina- 

 tion than has yet been made. Both the 

 conger and common eel have fringes along 

 the air bladder, which are probably the 



